2172981261 has 16 divisors (see below), whose sum is σ = 3166341120. Its totient is φ = 1314607920.

The previous prime is 2172981253. The next prime is 2172981289. The reversal of 2172981261 is 1621892712.

It is not a de Polignac number, because 2172981261 - 2³ = 2172981253 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2172981761) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39901 + ... + 77058.

It is an arithmetic number, because the mean of its divisors is an integer number (197896320).

Almost surely, 2^2172981261 is an apocalyptic number.

It is an amenable number.

2172981261 is a deficient number, since it is larger than the sum of its proper divisors (993359859).

2172981261 is a wasteful number, since it uses less digits than its factorization.

2172981261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117536.

The product of its digits is 24192, while the sum is 39.

The square root of 2172981261 is about 46615.2470871924. The cubic root of 2172981261 is about 1295.2452065204.

The spelling of 2172981261 in words is "two billion, one hundred seventy-two million, nine hundred eighty-one thousand, two hundred sixty-one".